Cattle Chat Podcast Summary

Episode: Sync Program, Repro Tech, Calf Weaning Age

Date: October 17, 2025
Host: Dr. Brad White
Guests: Dr. Jordan Thomas (University of Missouri), Dr. Bob Larson, Dr. Philip (last names not specified), Dustin (last name not specified)
Sponsor: ESTROTECT Robotics

Main Theme

This episode explores practical reproductive technologies in beef cattle, particularly how commercial producers can use synchronization and sexed semen to achieve herd goals. The panel also discusses the much-debated topic of optimal calf weaning age, grounding the conversation in both tradition and emerging best practices.

Key Discussion Points & Insights

1. Terminal vs. Maternal Herds: Practical Technologies

(Begins 04:00)

• Challenge:
  The beef industry’s market incentives push for maximally heavy steers, yet those same traits are not optimal for maternal replacement cows.

  • Jordan Thomas: “All the market signals right now are make them as big and as heavy as we possibly can… Some of those goals are… antagonistic to what we actually need in cows.” (04:10)

• Solutions Discussed:

  • Crossbreeding is underutilized and could help balance production goals.
    • Jordan Thomas: “If we could design some breeding systems that resulted in more effective use of crossbreeding, I think we’d really do ourselves a lot of good.” (05:00)
  • Artificial Insemination (AI) & Sexed Semen: Use AI in select, high-value cows to produce replacements, and conventional/terminal sires for the rest.
    • Bob Larson: “With artificial insemination, you can… select bulls for replacements, and natural service or other AI bulls for the terminal. Add sexed semen, and it has real potential.” (05:28)
  • Dairy Industry Analogy: The panel notes that dairies use sexed semen selectively to boost efficiency and create “beef-on-dairy” calves.
    • Jordan Thomas: “The lower third of the cow herd is all being bred to beef sires… that’s come about in large part because of sex semen and the ability to go make these Holstein heifers.” (07:01)

• Trade-Offs Identified:

  • Lower conception rates with sexed semen.
  • Early-calving cows (best for replacements) produce bigger calves, so using them for replacements can reduce weaning weights for those retained.

2. Managing Sexed Semen & Synchronization Programs

(Begins 11:44)

• Conception Rate Expectations:

  • Bob Larson: “On typical… not sex sorted semen… in cows that are cycling, I would expect to get 60 to 70%…” (10:15)
  • Jordan Thomas: “In cows that are cycling… it might be easily 70%... [With sexed semen] probably 0.8 to 0.85 [relative to conventional]. So… 50 to 60%.” (10:33–11:08)

• The Hidden Cost of Sexed Semen:

  • Lower conception rate means more open cows and reduced weaning weights, particularly since age at weaning is a key driver of calf weight.
    • Jordan Thomas: “The number one thing that makes a calf… weigh more at wean is just how old that calf is at the time of weaning… that is the hidden cost of using sex sorted semen.” (09:12)

• The 7 & 7 Sync Program:

  • The program aims to boost the proportion of cows expressing estrus before fixed-time AI, critical since cows not showing estrus respond very poorly to AI, especially with sexed semen.
    • Jordan Thomas: “If you put it [sexed semen] into a cow that hasn’t expressed estrus… her conception rates are just terrible… another great thing to do is limit the use of sex semen to… cows that actually express estrus before the time of fixed time AI [using] an estrotect patch or… heat detection aid.” (12:36)
  • The goal is a systems approach: precise candidate selection, matching protocols to cow history, and heat detection to maximize efficiency with higher-value technologies.

3. Selecting Cows for Repro Success

(Begins 15:08)

• Key Predictors for AI Success:
  • Most important: When the cow last calved. Early calvers have more postpartum recovery time, leading to higher conception rates.
    • Jordan Thomas: “The number one thing is: when did she calve last year?... that’s the number one driver of does she or does she not conceive back.” (15:42)
    • Long calving windows perpetuate late breeding; tighten with early preg diagnosis and selective culling.
  • Second: Body Condition Score. Cows ≥5.5 BCS do much better in AI programs.
    • Jordan Thomas: “If I’ve got cows in decent body condition… those cows are going to do exceptional in AI programs.” (16:31)

4. Q&A: What is the Best Age to Wean Calves?

(Begins 18:29)

• Historical Perspective:

  • The 205-day weaning standard was set in the 1960s for performance record-keeping, not necessarily best biological or economic practice.
    • Bob Larson: “It was kind of an average of a number of herds… it certainly doesn’t need to be carved in stone.” (19:05)

• Practical Flexibility:

  • Early weaning (even as young as 6 weeks) is possible and sometimes beneficial, particularly in drought or forage-limited situations.
    • Bob Larson: “You can actually wean beef calves pretty darn early… as early as six weeks of age… that actually works… it is doable.” (20:31)
  • Decide weaning timing based on operation-specific factors: forage condition, labor, market timing, and costs/returns on additional calf weight.
    • Philip: “A commercial producer… needs to be focused on what’s his cost of gain relative to… price slide for adding weight.” (21:00)
  • Dustin: “One size… doesn’t fit all… you’re going to have to figure out what works best for your own operation.” (21:47)

• Nutritional & Repro Impact:

  • Early weaning is often most valuable when cow condition starts to suffer. Best economic returns might come from weaning earlier to allow cows to regain BCS ahead of calving.
    • Jordan Thomas: “When cows start to slip in body condition, that is a great trigger to wean calves… it costs so much to put body condition back… the number one way is just get those calves pulled off a little bit earlier.” (21:55)

• Replacement Heifer Development:

  • Keeping heifer calves on doubtful-quality pasture can limit their development. Early weaning and targeted nutrition can accelerate puberty and breeding readiness.

Notable Quotes & Memorable Moments

• On herd division and AI system design:

  “If you’re a large enough herd… you could have a separate herd that’s really the maternal herd and the rest of the herd is terminal. That takes a really large herd… But with artificial insemination, you can do that.”
  — Bob Larson (05:20)

• On the "rich get richer" in breeding:

  “Cowherd, especially breeding, is a great example of where the rich get richer. If she’s calving early, she breeds early… it’s hard to break out if you get on the other end of that cycle.”
  — Brad White (17:29)

• On economic flexibility and tradition:

  “The 205 day age is a purebred target… a commercial producer shouldn’t even be worried about what age they are. I think he needs to be focused on what’s his cost of gain relative to… price slide for adding weight to those calves.”
  — Philip (20:43)

• On early weaning as a cow condition management tool:

  “Rebuilding cow body condition is such a costly thing to do if we let it get too low… that’s my number one trigger for… getting weaning actually accomplished.”
  — Jordan Thomas (22:21)

Segment Timestamps

• Trick play icebreaker: 00:40 – 03:10
• Terminal vs. maternal herd strategies; crossbreeding, AI, sexed semen: 04:06 – 11:44
• Synchronization protocols, 7 & 7 sync, targeting AI for best candidates: 11:44 – 15:42
• Selecting cows for optimal AI results, calving and BCS as key drivers: 15:42 – 17:29
• Listener Q&A – Best age to wean calves; history, economics, early weaning: 18:29 – 24:06

Tone & Takeaways

The episode maintains a collegial, practical tone. There’s a blend of technical discussion and real-world advice. While traditions like the “205-day standard” are respected, the consensus is producers should individualize practices to their environment and goals, using new reproductive and management technologies judiciously and always considering economic realities.

For commercial producers:

• Focus on what works for your system, not tradition for its own sake.
• Use technology to target replacements from your best cows, but understand the trade-offs.
• Adjust weaning age based on economics, pasture, and cow condition—not just industry averages.

Final thought:
Knowing the why and how behind decisions—whether breeding or weaning—empowers better choices for herd health, productivity, and profit.